FIG. 1A illustrates an exemplary prior art probing system used to test a device under test (“DUT”) 112, which may be, for example, one or more dies (not shown) on a newly manufactured semiconductor wafer or other electronic devices (e.g., previously manufactured dies). The probing system of FIG. 1A can include a test head 104 and a prober 102 (which is shown with a cut-away 126 to provide a partial view of the inside of the prober 102). To test DUT 112, the DUT is placed on a moveable stage 106 as shown in FIG. 1A, and the stage 106 is moved such that input and/or output terminals of the DUT 112 are brought into contact with probes 124 of a probe card assembly 108, which as shown, is attached to a test head plate 121. For example, the probe card assembly 108 may be bolted or clamped to the test head plate 121 with the probe substrate 122 and probes 124 extending into the prober 102 through opening 132 (see FIG. 1B).
Typically, a cable 110 or other communication means connects a tester (not shown) with the test head 104. The tester (not shown) generates test data to be written to the DUT 112, and the tester receives and evaluates response data generated by the DUT 112 in response to the test data. The cable 110 can provide a plurality of communications channels (not shown) to and from the tester (not shown) for such test and response data. Typically, there can be a communications channel (not shown) for each input and/or output terminal of the DUT 112, and there may be further communications channels for providing power and ground to the DUT 112.
The test head 104 and test head connectors 114 provide electrical connections that connect the tester channels (not shown) to the probe card assembly 108. The probe card assembly 108 shown in FIG. 1A can include a wiring board 120 and a probe substrate 122. The wiring board 120 provides electrical connections (not shown) from connectors 114 to a probe substrate 122, and the probe substrate provides electrical connections to the probes 124. The probe card assembly 108 thus provides an interface that connects the tester communications channels (not shown) to the input and/or output terminals (not shown) of a DUT 112.
While terminals (not shown) of DUT 112 are pressed against probes 124 (thus forming electrical connections between the terminals and the probes), the tester (not shown) runs tests on the DUT 112. For example, the tester (not shown) may run functional tests on the DUT 112 in which the DUT can be operated in various modes. Monitoring results of such operation, the tester (not shown) determines whether the DUT 112 functions properly. Such tests may also be used to determine a maximum reliable operating speed of the DUT 112. Parametric tests are another example of tests that may be run on the DUT 112. Parametric tests may include such things as measuring leakage current in the DUT 112, determining whether the DUT 112 has a short-circuit fault or open-circuit fault, etc.